Calling appliance for telephone-switchboards.



No. 650,487. Patented May 29, I900. C. E. SCRIBNER.

- CALLING APPLIANCE FOR TELEPHONE SW-IT-CHBOABDS.

(Application filed Feb. 9, 1899.)

(No Model.)

Witnesses: Inventor:

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ITE STATES PATENT OFFICE.

CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE \VESTERNELECTRIC COMPANY, OF SAME PLACE.

CALLING APPLIANCE Foe TELEPHoNE-swlTcHsoARos.

SPECIFICATION forming part of Letters Patent No. 650,487, dated May 29,1900.

Ap lication filed Eehruary 9118996 serial No. 705,107. (No model.)

To all whom. it may concern:

Be it known that I, CHARLES E.- SORIBNER, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have invented a certain new and useful Improvement in CallingAppliances for Telephone-switchboards, (Case No. 476,) of which thefollowing is a full, clear, concise, and exact description. I

This invention relates to calling signals for switchboards of thedivided multiple type, wherein each subscribers line is provided with anannunciator and answering-jack in each of two separate multipleswitchboards and with a multiple jack in each section of one of theswitchboards, the subscribers station being equipped withcall-controlling appliances by which the annunciator may be displayed oneither of the switchboards.

My present invention provides for the automatic operation of thedifferent calling signals in the switchboards and of supervisory signalstemporarily associated with united lines in either of the switchboards;and it consists in several novel features cooperating to this end.

One of the novel features consistsin the use of two telephones at thesubscribers station, each with a telephone-switch, with circuitconnections, whereby one of the telephones controls a call-originatingsignal at one of-the multiple switchboardsand theother controls asimilar signal at the other board.

Another feature consists in the combination, with any suitable means atthe substation for closing either a bridge of the line or a groundbranch from a conductor of the line at the option of the user, of twoserially-connected signal-controlling relays in'a bridge of the line,with a source of current at the central office and a ground branch fromthe bridge, whereby either or both relays may be rendered operative fromthe substation, and a device by which when one relay is operated onesignal is displayed or when both are operated another signal is given.

A third feature consists in a specific form of the device above alludedtonamely, a

Circuit including a source of current and a nected in a conductor 3,which is, in effect, di I00 resistance divided into two parallelbranches and two secondary signals, one in each of the branches, andswitch-contacts of one of the relays controlling each of the multiplebranches, one of the visible signals being adapted to shunt the otherwhile being itself displayed.

The invention is illustrated in the attached drawing. This diagramrepresents two telephone-lines entering a telephone-exchange andassociated therein with answering-jacks, line-signals, and multiplejacks on two different multiple switchboards Aand Bin accordance withthe type. Thus the line from station C is led to the switch-contacts ofan answering-jack o in a section A of the board A and to the likecontact-pieces of another answering jack c in a section B of the boardB, and thence to multiple jacks c and a, one

on each section A and A of the multiple switchboard A. Individualline-signals c and c are associated with the answeringjacks c and c inthe different switchboards A and B and are made operative through theagency of circuits which willpresently be described. Similarly the linefrom station D is connected with answering-jacks d and d in each of theboards A and B and with signals (1 and '01, associated with theansweringjacks, and is led to multiple jacked and d in two differentsections of the multiple switchboard B. By means of this arrangement ofparts the user of the telephone at either station C or D by operatingthe proper signal 0 or c? or d d may initiate a call upon either of themultiple switchboards on which the line of the required correspondentterminates, the subscribers being instructed in advance as to whichsignal must be operated to obtain connection with subscribers of eitherclass.

The telephone-substation is furnished with the usualtransmitting-telephone e, call-bell e, and with two receiving-telephonese and e each with a telephone-switch e and 6 respectively, on which itnormally rests. The hell 6 is connected permanently in a bridge of theline-circuit 1 2, together with-acoudenser. The transmitting-telephoneeis convided into multiple branches 4 and 5. In

' the former of these branches the receiver 6 is connected and in thelatter the receiver e which is grounded at the center of its winding.The branch 4 is controlled by the telephone-switch e of receiver 6 Thebranch 5 is-controlled by the other telephone-switch 6 supporting thereceiver 6 ceiver e be taken for use, bridge 3 4 of the line is closed,which includes the transmitting-telephone e and the receiving-telephonee If the other receiver 6 instead shouldbe raised from its support .for.use, a vgrounded bridge 3 5 would be closed.

At the central oflice'normal extensions 6 7 of the line-circuit are ledthrough the switchcontacts of a cut-off relay f and through themagnet-windings of two relays g and h to the poles of a battery 1',common to the different lines of the exchange. One pole of thisbatterythat which is connected with the relay h and line conductor 2-isgrounded or otherwise connected with a return-conductor lead ing to thebranch from the magnet-windin g of the receiver e Two relays g and h ofa line control the two signals 0 and c of the same line through theagency of a peculiar local circuit. This circuit consists of a mainportion 8,which includes a battery is and a resistancecoil Z and twomultiple branches 9 and 10, of which one includes the signal-lamp c andthe switch-contacts of relay g and the other signal c and theswitch-contacts of relay h. The voltage and current-carryingcapacity'ofeach of the lamps and c bear such a relation to the resistance of thecoill and the electronic-- tive force of battery 70 that either signalwill be lighted when its relay is operated, and the resistances andvoltages of the lamps are so adjusted with relation to each other thatthe lamp 0 shall shunt the lamp 0 when both branches 9 and 10 areclosed, the lamp 0 remaining lighted, however. These conditions areattained by a battery 76 of twenty-five volts, a resistance-coil l ofone hundred oh ms, a lamp 0 of fifteen volts taking one-tenth ampere,and a lamp 0 of four volts taking two-tenths ampere. All thespring-jacks of one line are furnished with secondary contact-pieces,which are united in a normallyopen portion 11 of a battery-circuit,which includes the exciting-magnet of the cut-off relay f. This circuitis placed in operative association with another circuit conductor toeffect the excitement of the relay in the act of making connection withthe line.

Each of the. switchboards is furnished at each of its multiple sectionswith the usual cord-circuits 12 and 13, terminating in plugs m and m. Asource of current a is connected in a bridge 14 of the plug-circuit withan impedance-coil between the source of current and each of theconductors of the cordcircuit to permit the use of a common source ofcurrent, while maintaining the independence with respect to telephoniccurrents of the different cord-circuits.

Thus if the re In the portion of conductor 13 leading to each of theplugs the magnet-winding of a relay is included, the relays beingdesignated 0 and 0 These relays control supervisory signals 19 and 1),associated with theditterent plugs. m and m, respectively, through theagency of shunts about the lamps, the lamps being in conductors 15 and16, respectively, leading to contact-pieces of the plugs designed toregister with the local contact-rings of the spring-jacks.

' The plug'circuits are equipped with listening and ringing keys in theusual arrangements, these parts being omitted from the drawing for thesake of clearness.

A person about to use the telephone at either station-for example,station G'must first ascertain in which group the line of the partywanted is to be found. This he may learn in accordance with the usualmethod by reference to a list. If the call should be for another lineentering the switchboard A, the callingsubscriber would take thetelephone e for use. This would close a ground branch from the lineconductor 1, which would permit the excitement of the relay g by currentfrom the central source. The excitement of the relay would close thebranch 9, including the signal-lamp 0 associated with the answering-jack c in the switchboard A, and the lighting of the lamp wouldconstitute a call to the operator in attendance. The operator would thenanswer I the call, test the line called for, of which she would find amultiple terminal-jack in her section of the multiple switchboard, andwould make the required connection, after which she would supervise theconnection by means of signals 19' and p, associated with the plugs mand m.

It the station with which connection is required by subscriber atstation 0 should be found in the group entering switchboard B, the userof the telephone at station 0 would take the telephone c for use. Thisact would permit the switch e to close a bridge of the line-circuit,which would complete a path for current from the central battery throughrelay g, line conductor 1, the bridge 3 4 at the substation, lineconductor 2, and the relay h. Both relays g and h being thus excitedwould close both branches 9 and 10 of the local signaling-circuit. Theclosure of branch 10,however, would divert from the branch 9 such aproportion of the current from battery as to maintain the dark conditionof lamp 0 but to illuminate lamp c. This lamp being associated with theanswering-jack c of the line in switchboard B would call for attentionfrom the operator, who having receivedthe order from the callingsubscriber would make the connection with a multiple jack of the line tothe called station in her section of the multiple switchboard B. Theinsertion of a plug to make connection with a line, whether 1 calling orcalled for, closes a local circuit 15 1-1 or 16 11, including the magnetof the cutoff relay f, and thus severs the normal ground tor 2 to thebattery it at the central office.

connections of the line and brings about the demagnetization of eitheror both the linerelays g and hand the extinction of the lamps which theycontrol.

It will be observed that the plugs and plugcircuits, with theirassociated mechanism, are alike in both the boards, so that thesupervisory signals 19 and 1) must be controlled at diiferent timesthrough the agency of telephone-switches e and c 0 is brought intoassociation with a line calling by means of a telephone e the relay isactuated by current flowing from the grounded battery n through lineconductor 1 to earth at the substation, while if the signal beassociated with a line at the station of which a telephone e is in usethe supervisory signal is in the path of current flowing over lineconductor 1, through the bridge 3 4 at the substation, and returning byway of line conduc- In either case the supervisory relay associated withthe line is in the path of current which is determined by thetelephone-switch of the telephone in use. The signals thus workuniformly under the varying conditions incident to the mode of calling.

I claim as new and desire to secure by Letters Patent 1. The combinationwith a telephone-line and appliances associated therewith at a centralstation in diiferent circuits, of several telephones at the substationand a telephoneswitch for each telephone, and different circuitconnections controlled by each of the switches adapted to cooperate withthe cir-- cuits of the different appliances, respectively, at thecentral otfice to actuate the said appliances, as described.

2. The combination with a telephone-line, of two signal-controllinginstruments associated therewith at a central office in differentcircuits of the line, two telephones at the substation and atelephone-switch for each, and circuit connections of each of theswitches adapted to form an operative circuit including a different oneof said signal-control1ing appliances, as described.

The combination with a telephone-line entering a divided switchboard andassociated with a call-indicating instrument in each of theswitchboards, of a telephone at the substation for each of saidcall-signals and a telephone-switch therefor, and circuit connections ofeach switch adapted to form a complete circuit including one of saidcallsignals, as described.

at. The combination with a telephone-line entering a divided switchboardand having a visible signal at each of said switchboards, one of saidsignals being in a bridge of the line-circuit with a source of current,and the other being in a ground branch from the linecircuit with asource of current, two switches at the substation, a bridge of the line0011- trolled by one of the switches, and a ground branch from the linecontrolled by the other,

If either relay 0 or whereby the operation of either switch displays thecorresponding signal, as described.

5. In combination, telephone-lines, each connected with ananswering-jack on one section of each of two divided boards, and with amultiple jack on each section of one of the boards, a signal-indicatorassociated with each of the answering-jacks, said signal-indicatorsbeing included in different circuits of the line, each with a source ofcurrent; switches at the substation, one for each of said signals, andcircuit connections of each switch adapted to cooperate with the normalcircuit of one of said signals to render the same operative; plugs andplug-circuits in each section of the switchboard for uniting lines, anda supervisory signal in each plug-circuit with a source of current, thecircuit of the supervisory signals forming operative circuitcombinations with the circuit connections controlled by each of theswitches at the substation, whereby the supervisory signals arecontrolled in a uniform manner by the different telephoneswitches, asdescribed.

6. The combination with a telephone-line,

of two signal-controlling magnets, means at the substation for closingcircuit through one of said signal-controlling magnets to display itssignal, means at the substation for closing circuit through both of saidmagnets, and a device actuated by the second magnet adapted to renderthe first-mentioned magnet inoperative to display its signal; wherebyeither of the signals may be alone displayed.

7. The combination with a telephone-line having an answering-jack and aline-signal at each of two switchboards, and a magnet associated withthe line controlling each of the line-signals, of a metallic circuitincluding both said magnets and a switch at the substation for closingthe circuit, a different circuit including one of said magnets and aswitch at the substation for closing that circuit, and means actuated bythe said magnet when excited adapted to render said firstmentionedmagnet inoperative to display its signal, as described.

8. The combination with a telephone-line and two signal-controllingmagnets connected with the line-circuit, and means for closing thecircuit through one of the magnets or through both, of a local circuitincluding a source of current and a resistance-coil and divided intomultiple branches, each of said branches being controlled by one of therelays, a signal-lamp in each of the branches, the lamp in one of thebranches being adapted to shunt the lamp in the other branch and to belighted by the shunted current, as described.

In witness whereof I hereunto subscribe my name this 31st day ofJanuary, A. D.'1899.

CHARLES E. SORIBNER.

Witnesses:

ELLA EDLER, ELIZABETH SIBLEY.

